With the most common form of glaucoma, open-angle glaucoma, there are no early symptoms. The only way to know if you have glaucoma before it causes irreversible vision loss is to have an eye exam. .
On the other hand, a far less common form of glaucoma, closed-angle glaucoma, has severe symptoms and is a medical emergency. Call your OCB eye doctor right away should you experience the following symptoms of an acute attack::
- Your vision is suddenly blurry
- You have severe eye pain
- You have a headache
- You feel sick to your stomach (nausea)
- You throw up
- You see rainbow-colored rings or halos around lights
If you are risk for glaucoma,due to risk factors you should not wait to have an eye exam. Otherwise:
If you have no risk factors or symptoms: You should have a comprehensive eye exam by age 40. This is the time when early signs of disease and changes in vision may begin. Based on the results of the initial screening, your OCB eye doctor will let you know how often to return for follow-up exams.
During your comprehensive eye exam, you OCB eye doctor will evaluate pressure in the eye through tonometry. (See Comprehensive Eye Exam). Normal pressure is 8 to 21 millimeters of mercury (mm Hg) but people with eye pressure in this range may still develop the disease. On the other hand, those who have slightly elevated pressure may not be destined to get glaucoma. How much stress the optic nerve can with stand varies from person to person.
If your OCB eye doctor suspects glaucoma, you can expect to undergo the following tests:
Your OCB eye doctor inspects your optic nerve for signs of damage using an ophthalmoscope, an instrument that magnifies the interior of the eye. Your pupils will be dilated (enlarged) with eye drops to allow your doctor a better view of your optic nerve.
A normal optic nerve is made up of more than one million tiny nerve fibers. As glaucoma damages the optic nerve, it causes the death of some of these nerve fibers. As a result, the appearance of the optic nerve changes. This is referred to as cupping. As the cupping increases, blank spots begin to develop in your field of vision.
If your eye pressure is not in the normal range, or your optic nerve looks unusual, your OCB eye doctor will perform the following glaucoma tests:
Gonioscopy allows your OCB eye doctor to examine the drainage angle of your eye and helps him or her to determine if you have open-angle glaucoma (where the drainage angle is not working efficiently enough), closed-angle glaucoma (where the drainage angle is at least partially blocked), or a dangerously narrow angle (where the iris is so close to the eye's drain that the iris could block it).
Permimetry (Visual Field Test)
The visual field test will check for blank spots in your vision. Your OCB eye doctor will be able to determine where blank spots appear in your field of vision. (See Comprehensive Eye Exam).
This test is used to measure the thickness of the cornea, the clear window at the front of the eye. A probe called a pachymeter is gently placed on the cornea to obtain this measurement. A very thin cornea may increase your risk of glaucoma.
Care for Glaucoma